Multi-polarized Reconfigurable Antenna with Ground Plane Slot and Capacitance Feeding for UAV-to-everything Communications

Abstract

This paper proposes a polarized reconfigurable antenna for unmanned aerial vehicles (UAVs) with flexible UAV-to-Everything (U2X) communications through a reduction of polarization loss. It operates at 2.45 GHz and consists of a square patch antenna, a capacitance feed, a ground surface slot, and a reconfigurable feeding network. The reconfigurable feeding network has dual polarization (linear, circular) depending on the configuration of the feeding network. The dual linear polarization reconfigurable feeding network configuration consists of a single-pole double-throw (SPDT) switch, a 50-ohm microstrip line, and a low-temperature co-fired ceramic (LTCC) 90-degree hybrid coupler. This was added to the circuit to form a double circular polarization reconfigurable feeding network. The proposed antenna has a miniaturized size (0.389λo×0.389λo×0.005λo), and is lightweight (12.2 g), making it suitable for low-height flight. Furthermore, it has maximum gains of 6.6 dBi and 7.2 dBi, in addition to an efficiency of 82%, and a 10 dB bandwidth of 4.5% (2.38-2.49 GHz). Therefore, the proposed antenna covers all UAV control links, video, and telemetry frequency bands (2.38-2.485 GHz).